Streets in Concepción, one of the towns hit hardest by the 27 February quake, filled over the weekend with fridges, televisions, toys, bicycles, mattresses and sofas during a brief amnesty.

Some analysts said it was because a "psychosis" that afflicted pillagers had lifted, while others attributed it to the arrest of 20 looters and warnings of further police sweeps, with those convicted facing from two to five years in jail.

It took 35 lorries to recover the looted goods, which police estimated was worth nearly $2m (£1.3m). The president, Michelle Bachelet, who yesterday toured a police gymnasium full of recovered goods, called the plundering one of "the other aftershocks of this tragic earthquake".

Those responsible would be prosecuted, she said.

"These are items that have nothing to do with survival. They reflect the moral damage of the people, some of whom came just to find things they could make money from."

Traders who raised prices to exploit desperation in the disaster area also faced prosecution.

The 8.8-magnitude quake was one of the most powerful recorded, devastating parts of central Chile and sending tsunamis crashing into coastal villages, killing more than 450 people.

Amid the chaos, power cuts, and food and water shortages some communities started ransacking shops for emergency supplies. That snowballed into a scramble for all types of goods, in houses as well as shops. Homeowners armed themselves with clubs and swords and burned tyres to protect their property.

Scenes of entire families – from children to grandparents – hauling away loot shocked a country that considered itself South America's most orderly, sophisticated nation.

"It was a collective psychosis. They didn't intend to do harm," Humberto Cifuentes, 53, a heavy machinery repairman, told Reuters news agency as police officers collected items left on the street in front of his home. "One person went out to steal, and then everyone followed. This was not done out of necessity. I can't explain it. It was unjustified."

Explanations that extreme inequality made the disaster an irresistible opportunity for the poor failed to impress most Chileans: a poll found 85% wanted the looters prosecuted.

Aran Fuentes, a city worker, lamented the damage to Chile's reputation. "After all we have done for other countries, to present ourselves to the rest of the world as looters really hurts."

A telethon for quake victims on Saturday restored a measure of pride and sense of solidarity by raising $58m, double the target sum. Reconstruction will cost an estimated $12bn to $30bn.

A poll by el Mercurio newspaper found 72% believed the government had responded late and inefficiently. Almost half of respondents said Bachelet, a moderate leftist who suffered under Augusto Pinochet's dictatorship, had waited too long to deploy troops because she did not want soldiers patrolling streets for the first time in two decades.

Some emergency response veterans, by contrast, praise the government for swiftly patching up crucial infrastructure and delivering huge quantities of aid to many – though not all – stricken areas.

Ban Ki-moon, the UN secretary-general, visited Concepción, where doctors warned of disease and health hazards from debris and lack of clean water. "Remember that we are with you ... our hearts are with you," Ban said.